i am an avid darkstalker disliker but would like to start with i will not be changing my opinion and 100% understand the same goes for you.
that being said:
darkstalker walked out of the egg with a hunger for power. there want anything arctic could have done to stop or change that. he wasn’t a good father by any means but it was not his fault, not entirely. darkstalker didn’t need teaching because he could see literally everything that could have ever been. he knew exactly what he was doing and there wasn’t one moment when he felt lost, not enough to try to get help. he wanted power. he was fully willing to do whatever it took to get that.
there was not one second in darkstalkers interactions with his so-called friends that he wasn’t manipulating them. even clearsight, the dragon who was supposed to be his soulmate, fell victim to his yearn for control. he enchanted and messed with her powers even after being explicitly told not to, demanding control as far as physically hurting clearsight as a final attempt. he wanted fathom to “freely” use his powers for darkstalkers own gain and was willing to get rid of indigo, whom he didn’t like simply because she saw through his bs, to do it.
even with moon, he manipulated and used her to get out of the mountain. he just about admitted it himself. there’s no ignoring what he did to anemone, or even fierceteeth. he wanted clearsight, he wanted to be loved, sure that’s true. but he enchanted a stranger to do it and wasn’t happy when the clearsight he fabricated didn’t turn out the way he wanted her to.
darkstalker knew what he was doing. he had every ability to see his error, but his own selfish, controlling nature was his downfall. he could have stopped. could have not sent that knife to kill icewings each year. could have not manipulated children. could have, perhaps, not made his father commit suicide in front of a crowd that his own sister was in. but he didn’t, and he didn’t because that’s the kind of dragon he is.
also, it was confirmed that darkstalker was based off of tui’s abusive ex. idk if that’ll do anything for ya.
tl;dr:
darkstalker brought his downfall upon himself and id be lying if i said i was disappointed with his “second chance”. he was hated, and rightfully so.